Why We Get Non-Authoritative Answer on NS Lookup

Have you noticed that your server might return Non-Authoritative Answer on NS Lookup which you never gave any importance? Here is why we get it. This is not an article to fix the Non-Authoritative Answer on NS Lookup, definitely we will discuss that part in future as guide but in this article we will discuss on a common but somewhat ignored stuff – the Non-Authoritative Answer on NS Lookup.

Why We Get Non-Authoritative Answer on NS Lookup?

To get the answer for the question why we get Non-Authoritative answer on NS Lookup like this :

 

We should know what is Authoritative answer on NS Lookup first. Authoritative relates to name server. Authoritative name server means, a name server which provides answers in response to questions asked about names in a zone.

The opposite of Non-Authoritative Answer is Authoritative-Only Answer. An authoritative-only name server give answers only to queries about domain names that have been specifically configured by the administrator of the server. Name servers can also be configured to give authoritative answers to queries in some zones. DNS provides a mechanism whereby the primary for a zone can notify all the known secondaries for that zone when the contents of the zone have changed. The contents of a zone are either manually configured by an administrator, or managed using Dynamic DNS.
A name server indicates that its response is authoritative by setting the Authoritative Answer (AA) bit in the response to a query on a name for which it is authoritative. Name servers providing answers for which they are not authoritative (for example, name servers for parent zones), do not set the AA bit.

We can use the nslookup tool in interactive mode. To do this, we need to run only nslookup command first and hit the return / enter key, which evokes the > , indicating an interactive session :

Basically, a non-authoritative name server is one that does not contain the records for the zone being queried. So, we actually should edit the files on the server too. On Cloud Server running on OpenStack, we can add PTR records easily, which fixes the PTR records return (after running the command set querytype=ptr). Depending on setup, it can be quite difficult to implement Authoritative-Only Answer.